Question

Teichoic acid is present in the cell wall of
A)Bacteriophage
B)Mycoplasma
C)Nostoc
D)Pneumococcus

Answer 1

Hint: It is a facultative anaerobic member of the genus streptococcus. These microorganisms are gram-positive bacteria and they are spherical in shape. This bacteria generally spread through contact with the people who are ill. The bacteria are also present in the back of the nose of healthy people.

Complete answer:
-Half of the dry weight of cell walls made up of the cell wall polymers known as Teichoic acids. These play a very important role in gram-positive bacteria's physiology and pathogenesis.
-It also helps in the regulation of the activity of cell wall hydrolases, cell wall elongation, and cell division in addition to the binding cell surface proteins. It also makes the bacterial resistance to antimicrobial peptides and interaction with the host factor.
-Two different types of acids are produced mostly by all the gram-positive bacteria. They are the wall Teichoic acid (WTAs) which is attached to the peptidoglycan and Lipoteichoic acid, which is attached to the membrane through glycolipid anchor.
-Gram-positive bacteria i.e Pneumococcus have a thick and highly complex cell wall that helps the cells to resist internal turgor pressure and also helps in maintaining their shape.
-Their cell wall is composed of a net-like peptidoglycan through which a Wall Teichoic acid is covalently attached. In addition to this, they have a Lipoteichoic acid which anchors to the membrane through a glycolipid moiety

Additional Information: Bacteriophage - it is a virus infects and replicates within the bacteria and archaea. These are ubiquitous virus means found wherever the bacterias exist.
Mycoplasma - they are simple one-celled organisms without outer membrane. They easily enter and infect the individual cells. Mycoplasma bacteria that occur in humans are Mycoplasma hominis and Mycoplasma pneumoniae.
Nostoc -they are found in gelatinous colonies that are composed of filaments called trichomes and inhabitant of both aquatic and terrestrial.

So, the correct answer is,” Pneumococcus”.

Note: -Streptococcus bacteria i.e Pneumococci spread through contact with the people who are ill. Healthy people carry this bacteria in the back of the nose. This bacteria causes mild or severe infections in human beings.
-The important constituents of gram-positive cell walls are the Teichoic acid, which comprises up to 50% of the weight of the cell wall.